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Predict/Guess the Number of Tornadoes and the First High Risk of 2016

andyhb

By andyhb,
in Central/Western States

Number of Tornadoes in 2016  

61 members have voted

  1. 1. Number of Tornadoes

    • Less than 900
      5
    • 900 to 1000
      3
    • 1000 to 1100
      6
    • 1100 to 1200
      14
    • 1200 to 1300
      15
    • 1300 to 1400
      15
    • 1400 to 1500
      1
    • Greater than 1500
      2

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andyhb

andyhb

Posted
Posted

Well unfortunately 2015's status as the least deadly year in the modern record has come undone in the final two weeks with two events claiming more than 10 lives (active December in strong Nino striking with a vengeance). It is that time to begin speculating about this upcoming season, since meteorological spring is ~2 months away once again.

Given that we will be moving out of a super Nino towards neutral ENSO and possibly into a La Nina by summer/fall (likely still with +PDO conditions although clearly not as robust as previous years), there are a number of factors that can be looked at. One is the strong sub tropical jet continuing and possibly offering severe threats to the Gulf coast and Florida (supported by other cases within El Nino events like 1983 and 1998). Won't be surprised if the S Plains end up active once again, although they tend to do better in weak/moderate Nino events. A late start to the season is possible given the fact that several strong Nino winters featured snowstorms in the SE well into March.

Overall, I'd expect a season somewhere near average this year, as most springs coming out of strong Ninos tended to hover around that (although there are some quite active ones like 1973 and 1998). 1958, 1983, 1966, etc. all fall into the average/perhaps slightly below average category.

Number of tornadoes: 1205

First high risk: April 22nd

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rockchalk83

rockchalk83

Posted
Posted

Some things to watch...

 

  • Drought is gone across KS/OK/TX/E CO....this will tend to hold the drylines west on some set ups. 
  • If the pattern we have seen so far this winter is a harbinger to spring, its possible we could see several multi-day severe weather episodes in the area mentioned above once the season gets going. 

I'll go with 1,150 tornadoes and the first high risk will be issued April 28th. 

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rolltide_130

rolltide_130

Posted
Posted

Some things to watch...

 

  • Drought is gone across KS/OK/TX/E CO....this will tend to hold the drylines west on some set ups. 
  • If the pattern we have seen so far this winter is a harbinger to spring, its possible we could see several multi-day severe weather episodes in the area mentioned above once the season gets going. 

I'll go with 1,150 tornadoes and the first high risk will be issued April 28th. 

 

With that in mind, I could see a more active Panhandle/SW Kansas season with activity continuing to uptick in that area. Barring this November's anomalous outbreak, there hasn't been major activity in that region since 2008 IIRC. 

 

With the decaying Nino, it'll be interesting to see if the STJ continues to pump in moisture like it did this past spring during setups. 

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Quincy

Quincy

Posted
Posted

I concur with most of the thoughts above. I feel that even going with a "near average" season may feel bullish compared to how the last four years have ended up, but there are at least some signs pointing toward increased severe activity.

 

I'm cautiously optimistic that this winter/early spring won't be as abysmal as we've seen since 2012. I also wouldn't rule out a high risk in March or early April, but I'll go with some "conservative" predictions below. The last week of April has performed fairly regularly in most years, including both slow seasons and active ones. The difference with most active seasons is that they tended to have a few bigger events in the February/March time-frame. The only exception with recent years was 2010, which despite a late start, also started to ramp up considerably in late April.

  • 1240 tornadoes
  • April 24th for first high risk

I can't help but feel that the relative long-term increase in rainfall over the southern Plains/Lower Mississippi Valley will at least contribute to higher quality moisture return, especially early in the season. The Gulf of Mexico SSTs are largely running positive anomalies as well, which shouldn't hurt, especially with S to SE low-level flow.

 

Here are a few stats that I posted in last year's thread, but with updated information:

 

Since 1988, (data is limited prior to this year) the "week" with the most high risk outlooks was April 23-29, with 10 out of 28 years (30%, down from 37% as of last year) having a high risk outlook in that period. The majority of these outlooks have been issued between April and May. Some spill out into June and occasionally both the winter and fall seasons have seen one.

post-533-0-31789600-1451679978_thumb.jpg

As far as the first high risk outlook in a given year, in years with a high risk, the average was April 14th. However, if you include 2000 and 2015, and allow the absence of such an outlook to push forward the average first date, then it moves to May 14th.

 

Month breakdown of first high risk outlook in a given year since 1988:

Jan: 1

Feb: 2

Mar: 7

Apr: 10

May: 2

Jun: 3

Nov: 1

 

For those interested, I also compiled a composite map of all high risk outlines since 2005. As expected, there are generally two clusters, one over the Plains and another near the Mississippi/Tennessee valleys. I went a step further to approximate what state they were centered over. Kansas is not a surprise and Arkansas seems to steal some thunder from Alabama/Kentucky/Mississippi/Tennessee, despite the fact that numerous high risk outlooks have covered those states. 

post-533-0-45937100-1451706101_thumb.png

post-533-0-62183700-1451680226_thumb.gif

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brettjrob

brettjrob

Posted
Posted

Some nice stats in this thread so far, good read. I concur with others in that we should again see a much higher ceiling for tornadoes over the southern High Plains region, relative to the drought-stricken 2011-2014 period we'd grown accustomed to. At least we should only have to worry about the synoptic pattern, then, rather than repeatedly squandering good setups due to a dry PBL.

 

2015 could've been quite a year for the Panhandles into W KS if not for the morning MCS train that lasted through much of April and May. Even despite that, it was still pretty decent overall, with several quality tornado days. Perhaps this spring will see a more balanced STJ influence over the southern Plains: enough to fend off drought, but not a runaway train of flooding events that overwhelm our setups, which are more dependent upon instability and the diurnal cycle relative to areas farther east.

 

It's important to remember, though, that short-term drought is largely what matters for severe weather season out here. 2015 proved that in a "good" way when an historic 4-5 year drought was rendered moot after just a few excessive rainfall events. My point is that if we somehow started skimping on precip heading into Feb-Mar, it could quickly become a problem, even if we maintained outrageous surpluses in the 6-12 month running totals. I doubt we see FMA go much below average (if at all) on precip with the strong Nino, though.

 

Some of you may remember last year that I posted about a crude method for scoring Plains chase seasons I developed in my spare time. I ran correlations for these scores against various teleconnection indices and found that the strongest leading indicator for spring activity, by far, is the preceding winter's mean AO value. In summary: we want to average a +AO through winter. December got us off to a nice head start, though we look to head negative for at least the first part of January, so that's maybe something to keep an eye on. Unsurprisingly, a wintertime +AO appears to have a stronger positive effect on early spring activity vs. late spring. (Note that even the one strongly -AO winter that turned out to be a "good" season, 2010, was very slow to start out in March and April).

 

The only other TC index I found to have a meaningful correlation with chase season quality was PDO, but unlike the AO, its value during the spring is more important than leading up to spring. If the PDO remains positive, it's statistically a negative for tornado activity in the central US -- but 2015 just proved that it's not a dealbreaker, even at relatively strong positive values.

For annual CONUS activity, my guess is truly a shot in the dark. I'll play it safe and go 1150. First HIGH risk April 26.

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Stebo

Stebo

Posted
Posted

I concur with most of the thoughts above. I feel that even going with a "near average" season may feel bullish compared to how the last four years have ended up, but there are at least some signs pointing toward increased severe activity.

 

I'm cautiously optimistic that this winter/early spring won't be as abysmal as we've seen since 2012. I also wouldn't rule out a high risk in March or early April, but I'll go with some "conservative" predictions below. The last week of April has performed fairly regularly in most years, including both slow seasons and active ones. The difference with most active seasons is that they tended to have a few bigger events in the February/March time-frame. The only exception with recent years was 2010, which despite a late start, also started to ramp up considerably in late April.

  • 1240 tornadoes
  • April 24th for first high risk

I can't help but feel that the relative long-term increase in rainfall over the southern Plains/Lower Mississippi Valley will at least contribute to higher quality moisture return, especially early in the season. The Gulf of Mexico SSTs are largely running positive anomalies as well, which shouldn't hurt, especially with S to SE low-level flow.

 

Here are a few stats that I posted in last year's thread, but with updated information:

 

Since 1988, (data is limited prior to this year) the "week" with the most high risk outlooks was April 23-29, with 10 out of 28 years (30%, down from 37% as of last year) having a high risk outlook in that period. The majority of these outlooks have been issued between April and May. Some spill out into June and occasionally both the winter and fall seasons have seen one.

attachicon.gifhigh_risk_freq_15.jpg

As far as the first high risk outlook in a given year, in years with a high risk, the average was April 14th. However, if you include 2000 and 2015, and allow the absence of such an outlook to push forward the average first date, then it moves to May 14th.

 

Month breakdown of first high risk outlook in a given year since 1988:

Jan: 1

Feb: 2

Mar: 7

Apr: 10

May: 2

Jun: 3

Nov: 1

 

For those interested, I also compiled a composite map of all high risk outlines since 2005. As expected, there are generally two clusters, one over the Plains and another near the Mississippi/Tennessee valleys. I went a step further to approximate what state they were centered over. Kansas is not a surprise and Arkansas seems to steal some thunder from Alabama/Kentucky/Mississippi/Tennessee, despite the fact that numerous high risk outlooks have covered those states. 

attachicon.gifhigh_risk_2005_2014GIF.gif

attachicon.gifhigh_risk_centeredGIF.gif

Your composite map is missing a high risk

 

day1otlk_20101026_1300_prt.gif

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